Thermally responsive transmission for automobile fan



June 27, 1961 R. s. ROOT THERMALLY RESPONSIVE TRANSMISSION FORAUTOMOBILE FAN 5 Sheets-Sheet 1 Filed Sept. 18, 1959 33 46 $3 INVENTOR"44 Robert S. Root 4, BY KARL :FLOCKS 42 .-ar-

ATTORNEY June 27, 1961 R. s. ROOT 2,990,045

THERMALLY RESPONSIVE TRANSMISSION FOR AUTOMOBILE FAN Filed Sept. 18,1959 3 Sheets-Sheet 2 l 22 04 34 I I /4 INVENTOR Robert 8. Root BY KAQLIFLOCKS ATTORNEY June 27, 1961 R. s. ROOT 2,990,045

THERMALLY RESPONSIVE TRANSMISSION FOR AUTOMOBILE FAN Filed Sept. 18,1959 3 Sheets-Sheet 3 9 man 12 1a eg NR I7 "2/ 19 N 76 a '75 U 17 I6 IRobert 5. Roof BY KARL LOCKS Ll ATTORNEY United States Patent Thepresent invention relates to a thermally responsive transmissionparticularly adapted for use with an internal I combustion engine havinga water jacket and cooling radiator, and more particularly to such atransmission for driving a fan in which the fan is supported by the pumpshaft so that aerodynamic forces generated by and in the fan are nottransmitted to the transmission. Also, the present invention will beseen to relate to a thermally responsive transmission for a fan in whichthe thermally responsive element is located so as to be unaffected bythe heat generated by the transmission.

Robert S. Root, the applicant in the instant application, is an employeeof the assignee Lipe-Rollway Corporation. Charles B. Space, nowdeceased, the applicant in application Serial No. 823,800 filed June 11,1959, for many years prior to his death and up until the time he passedaway was an employee of the Lipe-Rollway Corporation.

Many internal combustion engines are used under such conditions thatthey do not readily dissipate the heat that is generated by them and asa consequence in order to avoid overheating of these engines they arefurnished with jackets surrounding them in which a fluid is caused tocirculate, this fluid absorbing heat from the engine and giving up itsheat in a radiator. The radiator is simply a heat exchanger throughwhich the cooling water and air are caused to flow in heat exchangerelationship. In order to augment the flow of air, and thus the coolingof the water, a fan is used. Usually, the internal combustion engine isequipped with a water pump to circulate the water between the jacket onthe engine and the radiator, andthis water pump has a shaft that extendsoutwardly of the engine block and it is on this shaft that the fan isusually placed.

It has long been recognized that the direct driving of the fan is notdesirable because, for example, it consumes horsepower from the engineduring periods of use when augmented air flow for cooling purposes iseither not desired or useless, and also because the consumption ofhorsepower by the fan is constant despite the fact that the coolingwater needs varying amounts of heat removed therefrom under varyingconditions of use of the engine.

In order to overcome the deficiencies of the direct fan drive, there hasbeen proposed in the prior art several devices which sense thetemperature of the cooling water, either directly or indirectly, andcontrol the amount of torque transmited to the fan in relation to thetemperature of the cooling water. Such devices have not been completelysatisfactory in their operation, however, due to the fact that thetransmission included a clutch-like element and the thermally sensitiveunit used to sense the temperature of the water received heat generatedby the slipping clutch surfaces and thus reflected an erroneousindication of the temperature of the cooling water due to the addedamount of heat received from the clutch.

Also, these prior units were so constructed that forces created in andby the fan were transmitted through the interengaging clutch faces so asto interfere with their proper functioning. In particular, it is knownthat the forces transmitted through the clutch interengaging faces thatstarted out as fan aerodynamic forces cause variations in the torquetransmitted, and hence of the fan speed and also that there is causedthereby an undue amount of noise.

2,990,045 Patented June 27, 1961 An object of the present invention isto provide a transmission unit for an internal combustion engine fan inwhich forces arising from the fan are not transmitted through theinterengaging clutch faces.

Another object of the present invention is the provision of atransmission for a fan in which the operation of a clutch-liketransmission is not affected by fan generated forces.

A further object of the present invention is to provide a transmissionfor a fan that is so constructed that the fan is supported by relativelydirect connection with the pump shaft.

Yet another object of the present invention is the provision of asmoother, more reliable operation of a transmission unit for a fan.

Anotherobje'ct of the present invention is to provide a thermallyresponsive transmission for a fan in which the thermally responsive unitthereof is unaffected by heat of the transmission.

Yet another object of the present invention is the provision of athermally responsive transmission for a fan in which the thermallyresponsive unit is mounted remotely from the transmission heatgenerating parts.

Another object of the present invention is to provide a thermallyresponsive transmission for a fan which is readily removable by ordinarytools.

A further object of the present invention is the provision of athermally responsive transmission for a fan in which a minimum number ofrelatively small parts are utilized.

Still another object of the present invention is to provide a thermallyresponsive transmission for a fan that occupies a relatively smallspace.

Other objects and the nature and advantages of the instant inventionwill be apparent from the following description taken in conjunctionwith the accompanying drawings, wherein:

FIG. 1 is a front elevation of a thermally responsive transmission.

FIG. 2 is a cross-sectional view taken on the line 2-2 of FIG. 1,together with a showing of related parts to which the transmission isconventionally attached.

FIG. 3 is a cross-sectional view taken on the line 3-3 of FIG. 1.

FIG. 4 is a front elevation of a thermally responsive transmission inaccordance with the present invention.

FIG. 5 is a cross-sectional view taken on the line 55 of FIG. 4.

FIG. 6 is a cross-sectional view taken on the line 6-6 of FIG. 4.

Referring nOW to the drawings, wherein like reference characters areused to designate like or corresponding parts throughout the severalviews, there is shown in FIG. 2 a part 10 of an internal combustionengine, the part 10 having a pump shaft 11 extending therefrom towards aradiator (not shown) which is located forwardly or to the left thereof.Fixed on the pump'shaft 11 by any convenient means is a pulley 12 havinggrooves 13 to receive V-belts, not shown. It will be understood that theV belts serve to transmit torque from a driving pulley to the pulley 12.Pulley 12 also has a central strengthening plate 14 that is rotationallyfixed to shaft 11 and has bolt holes 16 therein.

Secured to the plate 14 by bolts 17 is a driving member 18 having acentral aperture 19 that engagingly receives the pump shaft 11. Drivingmember 18 has a hub 21 forwardly of the aperture 19 and a forwardlyinclined conical driving surface 22 in spaced concentric relation to thehub 21. Between hub 21 and surface 22, driving member 18 has a pluralityof peripherally spaced bolt holes 23 in which are received the bolts -17and a plurality of peripherally spaced air passages 24, it beingunderstood 3 that the air passages 24 are interspersed between the boltholes 23.

Supported in the hub 21 is an antifriction bearing 26 that is retainedagainst a shoulder 27 in hub 21 by a retaining ring 28 that is in turnheld by the bolts 17.

Bearing 26 rotatably supports the hollow shaft 31 of a carrier membergenerally designated 30. The rear end of hollowed shaft 31 has a groovein which is positioned a snap ring 32 that abuts against the rear faceof bearing 26 to prevent forward movement of shaft 31 With respect tobearing 26. An enlarged diameter of shaft 31 presents a shoulder 33 thatabuts against the forward face of bearing 26, so that it may be seenthat bearing 26 and carrier member 30 are fixed against relativelongitudinal movement. Forwardly of bearing 26 on hollow shaft 31 is abearing surface 33' and forwardly of bearing surface 33' is a disc 34.Disc 34 has fixed therein a plurality of peripherally spaced studs 36each of which extends forwardly and rearwardly of the disc 34 as shown.

A driven member 38 having a central aperture 39 is movably supported onthe supporting surface 33' of carrier member 30. Driven member 38 has aplurality of apertures 41 that are slightly larger than the rearwardlyextending parts of the studs 36 and hence loosely receives these partsof the studs 36. A rearwardly extending flange 42 of driven member 38has friction material 43 mounted therein, friction material 43 having aconical surface 44 that is in juxtaposition with the conical drivingsurface 22 of the driving member 18. As will be understood, it isthrough engagement of the driving surfaces 22 and 44 that torque istransmitted through and by the apparatus illustrated.

Referring now to PEG. 3, there may be seen in the rear face of disc 34 awell 46, and in the forward surface of the driven member 38 there may beseen a well 47. These wells are in opposed relation and a compressionspring 48 is seated in the wells 46 and 47 and urges the driven member38 rearwardly to thereby maintain the conical surface 22 and the conicalsurface 44 in contact and under pressure.

A thermally responsive element 50 is supported in and carried by theforward part of the disc 34 and has a rearwardly extending post 51 thatis rearwardly extensible upon an increase in temperature of element 50.Post 51 extends into the hollow of the shaft 31 of carrier member 30 andengages a transversely extending pin 52 that is in a relatively enlargedopening 53 in shaft 31. Opening 53 extends transversely through shaft 31between diametrically opposed points of the supporting surface 33'. Thepin 52 has a length that is greater than the diameter of shaft 31 atsupporting surface 33 and the ends thereof are received in recesses 54in driven member 38.

The disc 34 and driven member 38 have aligned peripherally spacedpassages 56 and 57 therein, respectively, as may be seen in FIG. 2 andthe passages 56 and 57 are at the same radial distance as the bolts 17to thus permit access to bolts 17. Also, the aligned passages 56 and 57permit air flow through the front of the unit as do the vents 58.

The forwardly extending parts of the studs 36 are adapted to receive afan F shown in dotted lines in FIG. 2.

In operation, with the parts assembled as is illustrated in FIG. 2, thepulley 12 will be driven by V-belts and will thus in turn drive the pumpshaft 11 and the driven member 18 through the intermediary of the bolts17. Carrier member 30 is supported in the bearing 26 for rotation, andas will be understood there can be no relative longitudinal movementbetween the hub 21, the bearing 26 and the carrier 30. Because of theurging of the springs 48 in the wells 46 and 47, the surface 44 offriction material 43 is urged into contact with the conical surface 22of driving member 18. Thus, torque will be transmitted through thesurfaces 22 and 44 and thus from driving member 18 to driven member 38.Because the rearwardly extending parts of the studs 36 extend throughthe apertures 41 in driven member 18, the drive will be transmitted bythe studs 36 into the disc 34 of carrier member 30. It will be recalledthat it is onto the disc 34 that the fan F is held, secured by nuts onthe threaded forwardly extending ends of studs 36.

It will be understood that when the air moving past the thermallyresponsive element is cool, and thus the post 51 is retracted, thetransmission unit described will not transmit the full amount of torqueavailable to the fan, but instead there will be some slippage betweenthe driving member 18 and driven member 38. Hence, it will be understoodthat there will be relative rotary motion between the driving member 18on the one hand and carrier member 30 and driven member 38 and fan F onthe other hand.

When the air moving past thermally responsive element 50 becomes heated,and thus there is a requirement for greater cooling and more work to beperformed by the fan F, the thermally responsive element 50 will becomeheated and post 51 thereof will extend and thereby there will be anincrease in the force exerted by post 51 on pin 52. This force will betransmitted by the ends of pin 52 to the parts of driven member 38 thatdefine the recesses 54 to thus cause even greater pressure at theinterengaging faces 22 and 44. Consequently, there will be transmittedto the fan F more torque to cause it to perform or work.

It will be understood that when fan F is rotated there are generatedbyit and on it various variable aerodynamic forces, and these forces aretransmitted from the blades into the central disc of the fan that isattached to the disc 34 of carrier member 30 by the studs 36. Theseforces are transmitted back through the shaft 31 of carrier member 30,the bearing 26, the hub 21 and thence into the pump shaft 11, thusavoiding transmission of these forces through the surfaces 22 and 44 andhence through the clutch-like portion of the transmission units. Thisresults in application of steadily applied forces only to theclutch-like surfaces 22 and 44 and thus the transmission unit operatesin a smooth manner. Also, due to the absorption of the fan forces by thestructure above set forth, there is a reduction in noise from the fan.

Also, it will be understood that the thermally responsive element 50 issupported by the carrier member 30 so that it is located remotely fromthe friction material 43 and the heat path from the friction material 43to the thermally responsive element 50 is through the driven member 38which has the apertures 58 as well as the apertures 57 therein to permitthe passage of cooling air. Accordingly, the heat generated in frictionmaterial 43 has no substantial effect on the thermally responsiveelement 50.

In FIG. 5, there is shown the part 10 of an internal combustion enginehaving the pump shaft 11 extending therefrom in the usual manner. Agrooved pulley 12 is connected with the pump shaft 11, and theconventional V-belts are used to drive the pulley 12 and the pump shaft11. The pulley 12 comprises a plate 14 having bolt holes 16 therein.

' Secured to the plate 14 of pulley 12 by bolts 17 fixed in the boltholes 16 is a driving member 18 having a central aperture 19 thatengagingly receives the pump shaft 11. Driving member 18 has a hub 21forwardly of the aperture 19 and an annular driving surface 62 in spacedconcentric relation to the hub 21. Driving member 18 also has, betweenhub 21 and driving surface 62, a plurality of peripherally spaced boltholes 63 for receiving the bolts 17.

Supported in the hub 21 is an antifriction bearing 26 that is retainedagainst a shoulder 27 in hub 21 by a retaining ring 28 that is in turnheld by the bolts 17 Bearing 26 rotatably supports a hollow shaft 64,which shaft 64 has a disc 65 fixedly connected thereto. Disc 65 may beseen to have threaded holes 66 for receiving bolts 67 for mounting a fanF.

An annular driven member 69 is mounted on the periphery of the disc 65in such a manner that it may move axially in relation thereto. Thedriven member 69 carries friction material 70 which has a contact facethereof parallel to the driving surface 62 of driving member 18.

A thermally responsive element 50 is threaded into the forward end ofshaft 64, and has a rearwardly extensible post 51 extending into thehollow of shaft 64.

An enlarged opening 53 extends transversely through the hollow shaftforwardly of the bearing 26, and a pin 72 extends through the opening 53and through radially extending aligned recesses 73 in the rear of disc65. The pin 72 has a length substantially equal to the diameter of theannular driven member 69, and is connected thereto, as by screws 74. Pin72 is smaller in thickness than the opening 53 in hollow shaft 64. Thus,the pin may move axially of the transmission device in the opening 53,and since the radial recess 73 in the rear of disc 65 is also largerthan the pin 72, the pin 72 may also move relatively to the disc 65 inan axial direction of the disc. However, the pin 72 may fit relativelyclosely in the sides of the recesses 73.

Within the hollow shaft 64 and rearwardly of pin 72 is a spring 75having one end thereof in engagement with the pin 72 and the other endthereof in engagement with an abutment 76 screw-threaded into the rearend of hollow shaft 64.

In FIG. 6, there is shown the pin 72 extending through the relativelygreater opening 53 in the hollow shaft 64, together with the post 51 ofthe thermally responsive element 50. It will be observed in FIG. 6 thatthe post 51 has not moved the pin 72 rearwardly, or to the left, and sothere is a space between the driving surface 62 of driving member 18 andthe friction material 70 carried by the driven member 69. This spacebetween the driving and driven surfaces is maintained by the spring 75acting on the pin 72.

As may be seen from FIG. 4, the disc 65 has indentations 77 in theperiphery thereof, through which access may be had to the bolts 17. As aconsequence, the assembly of the entire unit onto a pulley 12 is readilyaccomplished simply by placing the aperture 19 of driving member 18 ontothe pump shaft 11 and by then threading the bolts 17 into the holes 16in plate 14.

In operation, the pulley 12 will be driven by V-belts in known mannerand will therefore rotate both the pump shaft 11 and the driving member18. The spring 75 will tend to hold the pin 72 to the right, and thuswill tend to separate the driving member 18 from the driven member 69.This relationship obtains while the air moving past the thermallyresponsive unit 50 is relatively cool. Upon heating of such air,however, the post 51 of the thermally responsive element 50 extendsrearwardly, or to the left, as shown in FIGS. 5 and 6, and engages thepin 72 and causes the pin 72 to move rearwardly. This results inengagement of the friction material 70 with the driving surface 62 andthus the friction material 70, the driven member 69, the pin 72, disc 65and hollow shaft 64 are all caused to rotate in the same direction asdriving member 18. Since the fan F is secured to the disc 65, it willalso be driven during this time when hot air is impinging upon thethermally responsive element 50.

Upon a change in conditions so that cold air flows past the thermallyresponsive element 50, the post 51 will move to the right thus reducingthe pressure between the surface 62 and material 70, or removing contacttherebetween, entirely.

The transmission shown in FIGS. 4, 5 and 6 is made of a minimum numberof readily fabricated parts, and which parts are relatively small. Thetransmission shown in FIGS. 4 to 6 is, in assembled condition,relatively small, and thus occupies a minimum of space.

There has been provided a thermally responsive transmission for a fanwhich supports the fan substantially directly on the pump shaft thuseffecting quieter fan operation and steadier and more reliabletransmission unit operation. Also, the thermally responsive unit of thedevice is so located, by virtue of the structure provided, that itreceives no substantial amount of heat from the clutch-like transmissionunit.

It will be obvious to those skilled in the art that various changes maybe made without departing from the spirit of the invention and thereforethe invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appendedclaims.

What is claimed is:

1. In combination, a driving member having a central aperture adapted toengagingly receive the pump shaft of an engine therein, said drivingmember having a hub forwardly of said central aperture and an annulardriving surface perpendicular to the axis of said central aperture inspaced concentric relation to said hub, said member between said hub andsaid surface having peripherally spaced bolt holes, an anti-frictionbearing supported in said hub and a carrier member supported by saidbearing, said carrier member comprising a hollow shaft extending intoand supported by said bearing, a disc on and fixedly connected to saidhollow shaft and having holes therein adapted to receive fan-mountingbolts, an annular driven member mounted on the periphery of said discfor relative axial movement thereto and carrying friction materialhaving the face thereof parallel to and in juxtaposition with saiddriving surface, a thermally responsive element carried by the forwardpart of said hollow shaft and having a rearwardly extensible postextending into the hollow of said shaft, an enlarged opening extendingtransversely through said hollow shaft and a transversely extendingrelatively smaller pin in said opening engageable by the post of saidthermally responsive element, radially extending aligned recesses insaid disc, said pin extending through said recesses, means fixedlyconnecting said pin with said annular driven member, an abutment in saidhollow shaft rearwardly of said pin and between said pin and saidabutment for urging said pin forwardly.

2. In combination, a driving member having a central aperture adapted toengagingly receive the pump shaft of an engine therein, said drivingmember having a hub forwardly of said central aperture and an annulardriving surface in spaced concentric relation to said hub, anantifriction bearing supported in said hub and a hollow shaft extendinginto and supported by said bearing, a disc on and fixedly connected tosaid hollow shaft and having holes therein adapted to receivefan-mounting bolts, an annular driven member mounted on the periphery ofsaid disc for relative axial movement thereto and carrying frictionmaterial having the face thereof parallel to and in juxtaposition withsaid driving surface, a thermally responsive element carried by theforward part of said hollow shaft and having a rearwardly extensiblepost extending into the hollow of said shaft, an enlarged openingextending tnansversely through said hollow shaft and a transverselyextending relatively smaller pin in said opening engageable by the postof said thermally responsive element, radially extending alignedrecesses in said disc, said pin extending through said recesses, meansfixedly connecting said pin with said annular driven member, an abutmentin said hollow shaft rearwardly of said pin and spring means in saidhollow shaft between said pin and said abutment for urging said pinforwardly.

3. In combination, a driving member having a central aperture adapted toengagingly receive the pump shaft of an engine therein, said drivingmember having a hub forwardly of said central aperture and an annulardriving surface in spaced concentric relation to said hub, anantifriction bearing supported in said hub and a hollow shaft extendinginto and supported by said bearing, a disc on said hollow shaft andhaving holes therein adapted to receive fan-mounting bolts, an annulardriven member mounted on the periphery of said disc for relative axialmovement thereto and carrying friction material having the face thereofparallel to and in juxtaposition with said driving surface, a thermallyresponsive element carried by the forward part of said hollow shaft andhaving a rearwardly extensible post extending into the hollow of saidshaft, an enlarged opening extending transversely through said hollowshaft and a transversely extending relatively smaller pin in saidopening engageable by the post of said thermally responsive element,radially extending aligned recesses in said disc, said pin extendingthrough said recesses, means fixedly connecting said pin with saidannular driven member, and spring means in said hollow shaft urging saidpin forwardly.

4. In combination, a driving member having acentral aperture adapted toengagingly receive the pump shaft of an engine therein, said drivingmember having a hub forwardly of said central aperture and an annulardriving surface in spaced concentric relation to said hub, anantifriction bearing supported in said hub and a hollow shaft extendinginto and supported by said bearing, a disc on said hollow shaft, anannular driven member mounted on the periphery of said disc for relativeaxial movement thereto and having the face thereof parallel to and injuxtaposition with said driving surface, a thermally responsive elementcarried by the forward part of said hollow shaft and having a rearwardlyextensible post extending into the hollow of said shaft, an enlargedopening extending transversely through said hollow shaft and atransversely extending relatively smaller pin in said opening engageableby the post of said thermally responsive element, radially extendingaligned recesses in said disc, said pin extending through said recesses,means fixedly connecting said pin with said annular driven member, andspring means in said hollow shaft urging said pin forwardly.

5. In combination, a driving member having a central aperture adapted toengagingly receive the pump shaft of an engine therein, said drivingmember having'a hub forwardly of said central aperture and an annulardriving surface in spaced concentric relation to said hub, ananti-friction bearing supported in said hub, a hollow shaft extendinginto and supported by said bearing, a disc on said hollow shaft, athermally responsive element carried by the forward part of said hollowshaft and having a rearwardly extensible post extending into thehollowof said shaft, an enlarged opening extending transversely' throughsaid hollow shaft and a transversely extending relatively smaller pin insaid opening engageable by the post of said thermally responsiveelement, radially extending aligned recesses in said disc, said pinextending through said recesses, a driven member secured to said pin andhaving a face thereof parallel to and in juxtaposition with said drivingsurface, and spring means in said hollow shaft for urging said pinforwardly.

6. In combination, a driving member having a central aperture adapted toengagingly receive the pump shaft of an engine therein, said drivingmember having a hub forwardly of said central aperture and an annulardriving surface in spaced concentric relation to said hub, anantifriction bearing supported in said hub, a hollow shaft extendinginto and supported by said bearing, a disc on said hollow shaft, athermally responsive element carried by the forward part of said hollowshaft and having a rearwardly extensible post extending into the hollowof said shaft,'an enlarged opening extending transversely through saidhollow shaft and atnansversely extending relatively smaller pin in saidopening engageable by the post of said thermally responsive element,radially extending aligned recesses in said disc, said pin extendingthrough said recesses, a driven member secured to said pin and having aface thereof parallel to and in juxtaposition with said driving surface,and spring means for urging said pin forwardly.

Heiss June 24, 1958 Hardy Sept. 1, 1959

